var obj = { a: 1, b: 2 };
console.log(Object.getOwnPropertyDescriptors(obj));
Object.defineProperty(obj, 'c', {
    configurable: true,
    enumerable: false,
    value: 6,
    writable: false
});
console.log('c' in obj);
console.log(obj.hasOwnProperty('c'));
console.log(obj.propertyIsEnumerable('c'));
for (var key in obj) {
    console.log(key === 'c');
}
console.log(Object.keys(obj).includes('c'));
if (Object.isExtensible(obj)) {
    Object.preventExtensions(obj);
}
if (Object.getOwnPropertyDescriptor(obj, 'c').configurable) {
    Object.seal(obj);
    console.log(Object.isSealed(obj));
}
if (!Object.isFrozen) {
    Object.freeze(obj);
}
